Category Archives: Plants

Quiz: What Are These?

Quiz #1 (photo from Wikimedia Commons)

Today a Quiz. Here are two super sharp photos of plants from very different families. What are they?

Quiz #1: The top photo is a focus stack of 100 images. In real life the image would be 2mm wide so I think it’s been magnified about 80 times. (This one is hard to guess. It helps to squint your eyes to make it look small.)

Quiz #2: The photo below is a focus stack of 70 macro images. What it is?

Quiz #2 (photo from Wikimedia Commons)

If you’re desperate for clues, click the links on the captions to view the photo descriptions. Here’s a clue for #2: It’s edible.

Have an idea? Leave a comment with your answer.

p.s. In case you’re curious … Focus stacking is a digital processing technique in which the photographer takes multiple images of the same object at different focal points, then digitally merges the photos to produce a completely in-focus image. The object has to hold still and so does the camera. It requires special software to merge the images.

This video shows how it works.

(photos and video from Wikimedia Commons; click on the captions to see the originals)

Leaf Buds For Dinner

Brussels sprouts, plucked and on the stalk (photo by Kate St. John)

When I bought this stalk of Brussels sprouts, I wondered about the wild plant it came from. Did you know that cabbage, broccoli, cauliflower, kale, collard greens, kohlrabi and Brussels sprouts are all the same species? Every one of them is a cultivar of Brassica oleracea, also called wild cabbage.

Wild cabbage is a biennial that grows naturally on limestone sea cliffs in Europe. In its first year it’s a rosette of leaves. In its second year it blooms. As you can see by the flowers, it’s a member of the mustard family (Brassicaceae or Cruciferae).

Wild cabbage plant and flowers (photos from Wikimedia Commons)

Ten thousand years ago humans foraged for wild cabbage leaves. At the dawn of agriculture we began to cultivate them. One thing led to another, as described at Wikipedia:

  • Our preference for leaves led to kale and collard greens as cultivars.
  • We liked the tightly bunched leaves and the terminal leaf bud so we cultivated cabbage from the first-year rosette.
  • The Germans liked fatter cabbage stems so they cultivated kohlrabi. It’s not a root, it’s a bulbous stem.
  • People liked the tasty flower buds of the second-year plant so we cultivated cauliflower in the 1400s (flower is in its name) and then broccoli.
  • In Belgium they preferred the small leaf buds that grow in the leaf axils, so they bred Brussels sprouts in the 1700s.

While they’re growing, Brussels sprouts are nestled in the leaf axils like this.

As the stem gets taller the lower leaves turn yellow and fall off. Farmers and gardeners usually remove fallen leaves or prune them back.

Sometimes the weight of the plant bowls it over.

Brussels sprouts in a field (photo from Wikimedia Commons)

Eventually the plant is harvested and we buy Brussels sprouts in the store. Mmmmm! Leaf buds for dinner!

p.s. Did you know that Brussels sprouts are sweeter if they’re harvested after frost? Alas, most are harvested before that.

(first photo by Kate St. John, remaining photos from Wikimedia Commons; click on the captions to see the originals)

Outdoors in Early January

Privet berries, North Park, 1 Jan 2020 (photo by Kate St. John)

Sometimes we think Pittsburgh is boring in January but there’s still a lot to see outdoors. On New Years Day I joined the Botanical Society of Western PA for a walk in North Park. Here’s what we found.

Above, black privet berries (Ligustrum genus) stand out against the sky. Privet, an invasive plant, is found at the old farm along Irwin Road. The house and barn no longer stand but ornamental trees and shrubs remain, including the Ozark witchhazel (Hamamelis vernalis) we always trek to see. Our hike leader, Richard Nugent, said it will bloom pink in February. Here’s a bursting bud.

Ozark witchhazel buds, North Park Irwin Road, 1 Jan 2020 (photo by Kate St. John)

Unusual trees caught our attention, some with burls, others with holes. Two of the best are pictured below.

Large burl at North Park, 1 Jan 2020 (photo by Kate St. John)
A heart-shaped hole, North Park Irwin Road, 1 Jan 2020 (photo by Kate St. John)

We also saw and heard red-tailed hawks circling overhead. (example photo below)

Two red-tailed hawks soaring in winter (photo from Wikimedia Commons)

In January they claim territory with lots of circling and screaming. Here’s what they sound like. No, that is not the sound of an eagle.

During winter expect the unexpected. There’s more to see than you’d think.

(plant photos by Kate St. John, red-tailed hawk photo by Melissa McMasters via Wikimedia Commons; click on the caption to see the original)

So Many Robins!

American robin at an ornamental fruit tree (photo from Wikimedia Commons)

14 December 2019

Have you noticed it, too? There are so many robins in Pittsburgh right now!

American robins (Turdus migratorius) are versatile birds. They change their diet from insects and earthworms in summer to fruit in winter. They don’t care if it’s cold but they need lots of food in winter so they migrate more in response to food than to temperature.

Most robins move south in the fall but some remain north in large flocks that wander in search of abundant fruit. They choose Pittsburgh in December because we have lots of fruit on our native trees, ornamentals, invasive vines, and shrubs.

Here are just a few of the items on the robins’ menu.

Oriental bittersweet, Pittsburgh (photo by Kate St. John)
Bradford callery pear fruit, Pittsburgh, Nov 2012 (photo by Kate St. John)
Ornamental fruit tree, Dec 2019 (photo by John English)
Hackberries, a native tree (photo by Kate St. John)

When the fruit is gone and the ground is frozen, the robins will leave. I expect that to happen in early January.

(photos from Wikimedia Commons, Kate St. John and John English. Robin migration quoted from Journey North.)

A Very Thorny Problem

Invasive wineberry, Rubus phoenicolasius (photo by Kate St. John)

Last week this thorny alien showed off its armor in Schenley Park.

Wineberry (Rubus phoenicolasius) is an Asian member of the Rose family that was introduced to North America in the 1890s as breeding stock for raspberries. What a mistake! It became invasive in less than 100 years.

Wineberry is easy to distinguish from native raspberries because, in addition to thorns, the stems are coated with sharp red hairs. The stems look red from afar and dangerous up close.

Wineberry canes (Photo: Leslie J. Mehrhoff, University of Connecticut,

During the growing season wineberry resembles other raspberries with leaves that are white underneath and clustered flowers and fruits.

Wineberry leaves (photo by Leslie J. Mehrhoff, University of Connecticut,
Wineberry foliage and developing fruit (photo by Richard Gardner,

However, wineberry fruits are bright red.

Wineberry fruit (photo by Leslie J. Mehrhoff, University of Connecticut,

I’m sure the fruit is good for birds but it’s practically inaccessible to other wildlife because the plant is so formidable.

Whether you’re trying to pick its fruit, cross the thicket, or remove the plant, wineberry is a very thorny problem.

Read more about wineberry and its invasive properties at New York Invasive Species Information: Wineberry.

(first photo by Kate St. John, remaining photos from See photo credits and links to the originals in the captions.)

Dusty Blue Berries

Juniper berries, Cape Cod, 19 Oct 2019 (photo by Kate St. John)

Eastern redcedar or juniper (Juniperus virginiana) is a pioneer species that’s hard to find in Pittsburgh except where intentionally planted.

Junipers grow wild east of the Appalachians, offering their bluish berries to migrating birds. The berries are especially prized by robins, cedar waxwings, and catbirds.

(photo by Kate St. John)

What Have We Here?

Lichen on branches at the Lower Nine Mile Run Trail near Duck Hollow, 29 Oct 2019 (photo by John Bauman)

What have we here?

Lichens are two organisms that operate as one, a symbiotic partnership of a fungus with a green or blue-green algae (sometimes all three).  The algae’s photosynthesis feeds the fungus.  The fungus gathers and retains water and nutrients and protects the algae.

Those that grow on trees are epiphytes, totally dependent on the surrounding air and precipitation for their nutrition.  As they take in air, their tissues absorb suspended elements in concentrations that mimic the air quality.

Lichens can thrive in some of the harshest habitats on earth but epiphytes can’t live in the presence of air pollution, so we were really surprised to find them on our Duck Hollow walk on 29 October 2019 when the air smelled of rotten eggs.

The smell is hydrogen sulfide from US Steel’s Clairton Coke Works, 8 miles away. On cold calm days the pollution creeps up the Mon Valley and blankets Pittsburgh’s East End, a reminder of Pittsburgh’s Smoky City days.

The pollution happens all too frequently, as shown in these screenshots from on 28 and 29 Oct 2019. (SmellPGH is a crowd-sourced app for reporting air pollution smells. Many dark red triangles mean the air smelled really bad that day. Click here for more info.)

On the day before our walk the air was really bad, 28 Oct 2019 (screenshot from SmellPGH of 28 Oct 2019)
During our 29 October walk the worst smells were near the Mon River (screenshot from SmellPgh of 29 Oct 219)

We can smell hydrogen sulfide but not two dangerous air pollutants that travel with it: sulfur dioxide and particulate. Fructose lichens — the kind that stand out from the branch like those shown above — cannot survive in the presence of sulfur dioxide.

We were amazed. What have we here?

(photos by John Bauman, screenshots from; click on the captions to see the SmellPGH website)

A Brief Change Of Scene

The view from Fort Hill at Cape Cod, 18 Oct 2019 (photo by Kate St. John)

Travel is a tonic for seeing the world in new ways. This month my husband and I spent a week with his sister at Cape Cod where we had new weather, new scenery and new looks at plants I might have seen at home.

Our timing was pretty good. We missed the October 12 nor’easter but were on hand for the October 17 “bomb cyclone.” We didn’t lose power, but it was still very windy on the 18th when I visited Fort Hill, pictured above.

Birds were hard to find that day so I noticed plants such as this European spindle-tree (Euonymous europaeus) with puffy, pink, four-sided fruits.

European spindle-tree fruits, 18 Oct 2019, Dennis, MA (photo by Kate St. John)

The puffballs are actually a casing that holds orange fruit within. This ornamental has probably been planted in Pittsburgh, though I’ve never noticed it.

Euonymous europaeus fruits burst open (photo from Wikimedia Commons)

My favorite discovery was a hole in a leaf.

Someone ate this, Cape Cod, 20 Oct 2019 (photo by Kate St. John)

Who ate it? Perhaps this caterpillar did. I found him elsewhere on the plant.

And finally, the sun touched translucent red berries and made them glow at Bell’s Neck.

The small plants have a single leaf midway up the stem (lefthand photo) and were growing among pine needles. Please leave a comment to tell me what they are.

p.s. Thank you to Kerry Givens who identified the red berries as a Canada mayflower and the caterpillar as a Turbulent Phosphila moth.

(photos by Kate St. John except where noted in the captions; click the captions to see the originals)

October Plants

Japanese barberry, Moraine State Park, 13 Oct 2019 (photo by Kate St. John)

October weather is here and the trees are starting to change color in southwestern Pennsylvania. On the ground I found additional evidence of autumn last weekend.

Above, the shiny red fruits of Japanese barberry (Berberis thunbergii) hang from thorny branches. Watch out if you approach them, not because of the thorns but because of ticks. This invasive shrub creates thickets with the perfect micro-climate for black-legged ticks and their favorite host, white-footed mice.

Burdock, nature’s velcro, is still in bloom. The tiny hooks coating the sepal will soon dry out and cling to your clothes as you pass by.

Burdock still blooming, Moraine State Park, 13 October 2019 (photo by Kate St. John)

Though burdock (Arctium minus) is an alien invasive, a local insect has found it tasty. Notice the trail of the leaf miner, highlighted below.

Burdock with leaf miner activity, 13 Oct 2019 (photo by Kate St. John)

Meanwhile a native plant called Lycopodium or groundpine is in autumn dispersal mode. It has sent up tall pale green structures called strobili that will release the plant’s spores(*).

Lycopodium, Moraine State Park, 13 Oct 2019 (photo by Kate St. John)

Lycopodium is a very ancient plant. It’s the last living relative of Lepidodendron, a mighty tree that predates the dinosaurs.

(photos by Kate St. John)

(*) Spores definition from Google dictionary: Spores are minute, typically one-celled, reproductive unit capable of giving rise to a new individual without sexual fusion, characteristic of lower plants, fungi, and protozoans.